MANUFACTURING METHOD OF SEMICONDUCTOR STRUCTURE

A manufacturing method of a semiconductor structure includes the following operations. A stacked structure is formed on a substrate. The stacked structure includes semiconductor layers and sacrificial layers that are alternately stacked, in which the sacrificial layers include germanium, and germanium concentrations of the sacrificial layers decrease from bottom to top. A dummy gate structure is formed on the stacked structure. A spacer is formed on both sides of the dummy gate structure. The dummy gate structure is removed, thereby forming an opening. The sacrificial layers are removed from the opening. A gate structure is formed to cover the semiconductor layers. In another manufacturing method, the stacked structure includes semiconductor layers and sacrificial layers that are alternately stacked, in which thicknesses of the semiconductor layers increase from bottom to top, or thicknesses of the sacrificial layers increase from bottom to top.